System and method for inter-domain mobility management

ABSTRACT

The present invention relates to a method and apparatus for inter-domain mobility management for a telephony network. The present invention also relates generally to the H.323 standard for transmitting audio and video data streams, and more particularly to extending the H.323 standard to support mobility in a multimedia communication system with services over packet-based networks.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/201,195, entitled “Framework for H.323 inter-domain mobilitymanagement”, filed May 2, 2000, and is also related to “H.323 MobilityArchitecture for Terminal User and Service Mobility”, U.S. patentapplication Ser. No. 09/642,279, filed Aug. 18, 2000; “IntelligentSignaling Scheme for Computer-Readable Medium for H.323 MobilityArchitecture”, U.S. patent application Ser. No. 09/642,298, filed Aug.18, 2000 and issued May 4, 2004 as U.S. Pat. No. 6,732,177; “H.323Back-End Services for Intra-Zone and Inter-Zone Mobility Management”.U.S. patent application Ser. No., 09/801,914, filed Mar. 9, 2001; and“H.323 Mobility Protocol for Terminal User and Service Mobility”, U.S.patent application Ser. No. 09/642,142, filed Aug. 18, 2000 and issuedAug. 10, 2004 as U.S. Pat. No. 6,775,255; all assigned to the assigneeof the instant application, and the disclosure of each is herebyentirely incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a method and apparatus for inter-domainmobility management for a telephony network. The present invention alsorelates generally to the H.323 standard for transmitting audio and videodata streams, and more particularly to extending the H.323 standard tosupport mobility in a multimedia communication system with services overpacket-based networks.

BACKGROUND OF THE INVENTION

A framework on how the inter-domain communications need to be done inH.323 for mobility management has been provided in the context of theexisting H.225.0 Annex G standard, as disclosed in ITU-T RecommendationH.225.0 Annex G (1999), “Communications Between Administrative Domains”.The communication flows for mobility management considering the BE(Border Elements), Gatekeepers (GKs), Home location function (HLFs), anddomains where each entity can be arranged in any logical architecturalrelationship: Centralized, Distributed, and/or Hybrid Architecture.ITU-T Recommendation H.323 describes terminals and other entities thatprovide multimedia communications services over packet based networks(PBN) which may not provide a guaranteed Quality of Service. H.323entities may provide real-time audio, video and/or data communications.Support for audio is mandatory, while data and video are optional, butif supported, the ability to use a specified common mode of operation isrequired, so that all terminals supporting that media type caninterwork.

The inter-domain mobility management of this invention needs to beindependent of the underlying architectural configurations and is not“hard-wired” for any particular configuration of any architectural orfunctional entity as done in the prior art.

The new messages for mobility management within a domain has beenproposed for H.225.0 RAS (Intra-domain communication) messages.Similarly, for inter-domain mobility management we need to extendH.225.0 Annex G, as disclosed in ITU-T Recommendation H.225.0 Annex G(1999), “Communications Between Administrative Domains.” The newmessages, such as, disclosed in R. R. Roy, AT&T, “H.323 MobilityArchitecture and Protocol for Terminal, User, and Service Mobility,”D-354, ITU-T SG 16 Q.13/16, WP2, Geneva, Switzerland, Feb. 7-18, 2000,the disclosure of which is entirely incorporated herein by reference,required for mobility binding and updating will also be applicable forinter-domain communication with additional parameters like hopcounts andothers in the header as required per H.225.0 Annex G.

In addition, the existing H.225.0 RAS messages like LRQ (LocationRequest) such as, disclosed in R. R. Roy, AT&T, “H.323 MobilityManagement Services, Scenarios, and Information Flows in anAdministrative Domain,” MD012, Ad Hoc Mobility Conference Call,February-May 2000, have been extended to manage mobility forintra-domain communications. Similarly, the messages like accessRequestand others of H.225.0 Annex G are also need to be extended forinter-domain mobility management as described in this embodiment.However, the mobility related parameters that specify the informationrelated to the mobile entity used in the LRQ and call signaling messagesof H.225.0 RAS/Q.931 also need to be passed to the accessRequest andother messages of H.225.0 Annex G while the mobile entity is visiting aforeign domain.

It is also the critical need for a mobile entity to have an optionwhether it will let others to know its present location in a foreigndomain because of security or other reasons while it is away from itshome domain. If the mobile entity does not want to make its addresspublic while it is visiting in a foreign domain, the communications needto be done via mobile entity's home network address that it may wantmake to public.

Originally, the International Telecommunications Union (ITU) developedH.323 as an adaptation of H.320, which addresses videoconferencing overISDN and other circuit-switched networks and services. ITU-TRecommendation H.320 describes terminals and other entities that providemultimedia communications services over circuit-switched networks whichprovide a guaranteed Quality of Service. H.320 entities may providereal-time audio, video and/or data communications. H.320 was ratified in1990, and corporations expanded their networks to include Local AreaNetworks (LANs) and LAN gateways to the Wide Area Network (WAN). Then,H.323 was expanded beyond being an extension of H.320 so that H.323 nowcovers the corporate intranets and packet-switched networks in general.The ITU published a set of standards for multimedia communication overpacket-based networks (PBNs) under the H.323 designation, which includesstandards for data channels, monitoring channels, and control channels.It includes provision of real-time audio, video and/or datacommunications. The H.323 components defined by the standard include:terminals, gateways, gatekeepers and multipoint control units (MCUs).The terminals provide real-time communications, must support audio/voicecommunications and optionally s support data and video. The most commonH.323 terminals are the applications that run on a personal computer(PC). H.323 gateways provide services to H.323 clients and allowcommunication with non-H.323 entities, such as communication betweenH.323 terminals and telephone in a circuit-switched network. Gatekeepersprovide call control services for H.323 endpoints, e.g., addresstranslation and bandwidth management. Gatekeepers are optional in theH.323 standard, but, if they are present, the endpoints must use theservices of the gatekeepers. The H.323 standard specifies certainmandatory services that gatekeepers, if utilized, must provide. Themultipoint control units provide support for conferences of three ormore endpoints by managing conference resources, manage negotiationsbetween the endpoints to specify which audio or video code(s) to use andmay manage the media stream. The H.323 standard defines how audio andvideo conferencing systems communicate over packet-switched networksdefines call control and management practices for point-to-point andbroadcast/multicast/unicast multipoint conferences, addresses QoS issueswith a centralized gatekeeper that LAN administrators use to managemedia traffic, bandwidth and user participation, and describesfunctionality that allows calls to connect from the LAN to the PublicSwitched Telephone Network (PST) as well as to otherH.32×standards-based terminals.

In version 2 of the H.323 standard, video and audio data streams arecompressed and packetized in accordance with a real-time transportprotocol (RTP/RTCP) standard from the Internet Engineering Task Force(IETF) and are used to support video conferencing and othercommunications over the Internet. Packets include data and headerinformation which facilitates detection of packet loss, detection ofpacket status and synchronization of the packets. The video data streamsmay use H.261, H.262, or H.263 protocols. Audio data streams may useG.711, G.722, G.723.1 G.728 or G.729 protocols. Generally, the H.323standard supports teleconferencing in networks that utilize TCP/IP, suchas, for example, the Internet.

The H.323 system supports interoperability and assumes that users,terminals, and services are fixed. If an H.323 terminal is moved formone network to another, its point of attachment or network addresschanges. In this situation, the address of the mobile terminal needs tobe resolved to set up a new call or continue a same call. Thus, there isa need for an H.323 mobility architecture that provides for terminal,user and service mobility for inter-domain mobility management.

SUMMARY OF THE INVENTION

The present invention provides an H.323-based mobility protocol forreal-time inter-domain mobility management for a telephony networkbetween the administrative domains.

Therefore, in one aspect the invention is an inter-domain mobilitymanagement method, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity;

(d) said second border element communicates sending back with to saidfirst border element with information to resolve information thatresolves said information related to the mobile entity; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In another aspect the invention is an inter-domain mobility managementmethod, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain having a first backend services;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity;

(d) said second border element obtains information obtaining from asecond backend services in said second administrative domain informationthat resolves said information related to the mobile entity andcommunicates sending back with to said first border element withinformation to resolve said information related to the mobile entity theinformation obtained from said second border element; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In yet another aspect the invention is an inter-domain mobilitymanagement method, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain having a first backend services;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing afirst backend services to resolve said information related to the mobileentity, wherein said first backend services is shared with both by saidfirst administrative domain and a second administrative domain;

(d) said second first border element obtains information obtaining fromsaid first backend services in said first and said second administrativedomain information that resolves said information related to the mobileentity, and communicates sending it back to said first border elementwith information to resolve said information related to the mobileentity; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In still another aspect the invention is an inter-domain mobilitymanagement method, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain having a first backend services;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity;

(d) said second border element obtains obtaining information from asecond backend services in said second administrative domain via atleast one a second gatekeeper in said second administrative domain andcommunicates back with sending back to said first border element withinformation to resolve said information related to the mobile entity theinformation obtained from the second backend service; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In still yet another aspect the invention is an inter-domain mobilitymanagement method, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain having a first home location function;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity;

(d) said second border element obtains obtaining information from asecond home location function in said second administrative domain andcommunicates sending back with to said first border element withinformation to resolve said information related to the mobile entity theinformation obtained from the second location function; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In yet another aspect the invention is an inter-domain mobilitymanagement method, comprising:

(a) a mobile H.323 entity communicating sending information related tothe mobile entity with to a first gatekeeper in a first administrativedomain having a first home location function;

(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administrative domain toresolve said information related to the mobile entity;

(c) said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity;

(d) said second border element obtains obtaining information from asecond home location function in said second administrative domain viaat least one a second gatekeeper in said second administrative domainand communicates sending back with to said first border element withinformation to resolve said information related to the mobile entity theinformation obtained from said second location function; and

(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.

In still another aspect this invention is an H.323-based mobilityprotocol for real-time mobile multimedia communications and conferencingover packet-based networks by a Mobile Terminal/Node/Entity having aHome Gatekeeper/Home Database, comprising the steps of:

upon becoming mobile and initiating an H.323 communication that includesat least one of: audio, video and data, by the MobileTerminal/Node/Entity, with respect to notification, one of:

providing, by at least one of a plurality of available H.323Visiting/Foreign Gatekeepers in a first administrative domain,notification of H.323 mobility services availability by periodicallybroadcasting/multicasting/unicasting a Mobility GatekeeperAdvertisement; and

where the Mobile Terminal/Node/Entity lacks notification of H.323mobility services availability, broadcasting/multicasting/unicasting/sending, by the Mobile Terminal/Node/Entity, a message to the HomeGatekeeper/Home Location Database in a second administrative domain,which notifies H.323 Visiting/Foreign Gatekeepers that the MobileTerminal/Node/Entity needs H.323 mobility services and notifying, by theH.323 Visiting/Foreign Gatekeepers, to the Mobile Terminal/Node/Entityof available H.323 Visiting/Foreign Gatekeepers within the firstadministrative domain;

registering, by the Mobile Terminal/Node/Entity, with a H.323Visiting/Foreign Gatekeeper of the available H.323 Visiting/ForeignGatekeepers that support H.323 mobility services; and

providing, for the Mobile Terminal/Node/Entity by the H.323Visiting/Foreign Gatekeeper with which the Mobile Terminal/Node/Entityis registered, support for the H.323 communication that includes atleast one of: audio, video and data.

In yet another aspect this invention is a computer-readable mediumhaving computer-executable steps for implementing, by a MobileTerminal/Node/Entity, an H.323-based mobility protocol for real-timemobile multimedia communications and conferencing over packet-basednetworks wherein a plurality of H.323 gatekeepers provide notificationof H.323 mobility services availability by periodicallybroadcasting/multicasting/unicasting a Mobility GatekeeperAdvertisement, comprising the computer-executable steps of:

where the Mobile Terminal/Node/Entity becomes mobile and initiates anH.323 communication that includes at least one of: audio, video anddata, by the Mobile Terminal/Node/Entity, with respect to notification,one of:

providing, by at least one of a plurality of available H.323Visiting/Foreign Gatekeepers within a first administrative domain,notification of H.323 mobility services availability by periodicallybroadcasting/multicasting/unicasting/sending a Mobility GatekeeperAdvertisement; and

where the Mobile Terminal/Node/Entity lacks notification of H.323mobility services availability,broadcasting/multicasting/unicasting/sending, by the MobileTerminal/Node/Entity, a message to the Home Gatekeeper/Home LocationDatabase in a second administrative domain, which notifies H.323Visiting/Foreign Gatekeepers that the Mobile Terminal/Node/Entity needsH.323 mobility services and notifying, by the H.323 Visiting/ForeignGatekeepers, to the Mobile Terminal/Node/Entity of available H.323Visiting/Foreign Gatekeepers within the first administrative domain;

registering, by the Mobile Terminal/Node/Entity, with a H.323Visiting/Foreign Gatekeeper of the available H.323 Visiting/ForeignGatekeepers that support H.323 mobility services; and

providing, for the Mobile Terminal/Node/Entity by the H.323Visiting/Foreign Gatekeeper with which the Mobile Terminal/Node/Entityis registered, support for the H.323 communication that includes atleast one of: audio, video and data.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elementscharacteristic of the invention are set forth with particularity in theappended claims. The drawings are for illustration purposes only and arenot drawn to scale. Furthermore, like numbers represent like features inthe drawings. The invention itself, however, both as to organization andmethod of operation, may best be understood by reference to the detaileddescription which follows taken in conjunction with the accompanyingdrawings in which:

FIG. 1 illustrates an embodiment of the Inter-Domain Mobility Managementsystem of this invention which illustrates communications between twoadministrative domains.

FIG. 2 illustrates another embodiment of the Inter-Domain MobilityManagement system of this invention with backend services.

FIG. 3 illustrates yet another embodiment of the Inter-Domain MobilityManagement system of this invention where requests are resolved by thebackend server shared among multiple administrative domains.

FIG. 4 illustrates still another embodiment of the Inter-Domain MobilityManagement system of this invention where requests are resolved by thebackend server not shared among multiple administrative domains.

FIG. 5 illustrates yet another embodiment of the Inter-Domain MobilityManagement system of this invention using centralized home locationfunction servers/databases.

FIG. 6 illustrates still another embodiment of the Inter-Domain MobilityManagement system of this invention using distributed home locationfunction servers/databases.

DETAILED DESCRIPTION

The present invention provides for extending the H.323 standard tosupport mobility in a multimedia communication system with services overpacket-based networks. The present H.323 standard is known to thoseskilled in the art and is hereby incorporated by reference. Theinvention supports extending H.323 to support mobility in a transportindependent way, create new H.323 messages and/or message elements thatneeded to support mobility, and facilitate interoperability forimplementation of H.323 mobility over specific networking environmentssuch as wireless/PSTN-IP-LAN. The invention provides for extension toexisting H.225.0 (H.323) messages to accommodate mobility. Messages areprovided to facilitate mobility binding as the mobile entity moves formone place to another. H.323 mobility service varies from traditionalservices such as cellular wireless/PSTN, and mobile IP, mobilityservices in that the IETF=s mobile protocol may be modified to includean interworking function (IWF) to provide interoperability between themobile H.323 system and the wireless-PSTN mobile network.

When a mobile unit implementing H.323 uses a packet-based network, e.g.,the IP subnet, together with an H.323-based point of attachment (e.g.,network point of attachment, zone, domain), the mobility information ismanaged via a gatekeeper. There may be a gatekeeper at the transmittingend and at the receiving end also. If necessary, the gatekeeper can alsoperform bandwidth management, address translation, maps LAN aliases toIP addresses, and sets up a real-time transport control protocol (RTCP)for exchanging status information between the transmitting end and thereceiving end. A H.245 control channel is set up to provide controlfunctions such as, for example, opening and closing data channels.

The functional requirements of H.323 mobility are primarily described atthe H.323 application level as:

Terminal Mobility: the ability for a terminal to changes location,network point of attachment, and H.323 point of attachment and still beable to communicate. A fixed or mobile H.323 terminal must be able toreach an H.323 mobile user and vice versa. Conversations are providedeven when the mobile terminal moves from one place to another with adifferent point of attachment or network address. Where desired,communications are also provided among the H.323 mobile users.Intra-zone, inter-zone (intra-domain) and/or inter-domain handoff issupported. Handoff between intra-zone, inter-zone (intradomain) and orinter-domain users is supported.

User Mobility: the ability for a user to maintain the same user identityon different terminals or terminal types. An H.323 user maintains thesame identity and may receive the same or, where desired, differentservices even when the user moves. Service providers may be switchedwith the user maintaining the same identity.

Mobility Management: The H.323 mobility management is supported toprovide registration, call establishment, roaming and handoff.

QoS Support: QoS service is maintained during intra-zone, inter-zone(intra-domain) and/or inter-domain roaming for the H.323 user.

Authentication and Security: Authentication and security mechanisms areprovided in support of H.323 mobility.

Typically, a gatekeeper (GK) manages a zone. A zone is generally acollection of H.323 entities such as terminals, gateways (GWs) orinterworking functions (IWFs) and multi-point controllers (MCs). EachH.323 entity has a unique network point of attachment or address, andeach zone may contain many network points of attachment, subnets, oraddresses under the management of a GK. For example, a zone many havemultiple networks in the case of an IP, ATM, or other network. If a useror terminal moves within a zone, its network attachment or subnetworkaddress may also change.

A domain may consist of a single or of multiple zones. Thus, H.323mobility is addressed in terms of zones and domains as well. If an H.323user, entity or terminal crosses a zone boundary, such a change may betermed as a change of H.323 point of attachment because an H.323gatekeeper manages the registration of all H.323 entities in a givenzone. In addition, H.323 services are ensured during the call andbetween calls while users or terminals move from place to place.

Other terminology used herein is:

Discrete terminal mobility or roaming: the ability for a terminal tomake discrete changes of physical location, i.e., to change locationwhile no media streams are active.

Continuous terminal mobility or handover: the ability for a terminal tochange location while media streams are active. Such a change may beseamless, i.e., without loss of data, or alternatively, may not beseamless, i.e., wherein some media stream data is lost.

Service mobility: the ability for a user to obtain a particular serviceindependent of user and terminal mobility, i.e., wherein a foreignnetwork has the means to obtain the parameters required for the service.

Network Point of Attachment: the attachment or address, e.g., an IPaddress, of an H.323 entity, e.g., terminals, MCUs, MCs, and/or GWs, toa network. Similarly, the network point of attachment for ATM and othernetwork can also be defined. Each H.323 entity has at least one networkaddress which uniquely identifies the H.323 entity on the network. Theaddress is specific to the network environment in which the endpoint islocated. Different network environments may have different networkaddress formats. H.323 permits an endpoint to use different networkaddresses for different channels within the same call.

H.323 Point of Attachment: the gatekeeper with which an H.323 terminal,GW (IWF), MC, or MCU is Databased.

Mobile Entity: the H.323 entity that changes its point of attachment(network and/or H.323 point of attachment) from one attachment toanother. A mobile entity can continue to communicate with other H.323entities at any location as it moves from place to place.

Home GK: a gatekeeper in the mobile entity's home zone which performsthe necessary management functions for departed mobile entities andmaintains current location information for each. Any H.323 GK thatprovides the support for H.323 mobile entities can act as a home GK.

Home Network: the network in the mobile entity's home network and thenetwork which has been declared by the mobile entity as its homenetwork, e.g., an IP subnetwork in the home zone declared as a homenetwork by a mobile entity.

Home Network Address: the address of the network point of attachment inthe home network of a mobile entity, e.g., IP address (RAS transportaddress) in a home IP subnetwork. If the transport address contains thenetwork address in addition to the TSAP, the home transport address willalso contain the home network address.

Foreign GK: a gatekeeper on a mobile entity's visited- or visiting-zonewhich cooperates with the home GK to have the information related to themobile entity while it is away from its home zone. Any H.323 GK thatprovides the support for H.323 mobile entities can act as a foreign GK.

Foreign Network: the network in the mobile entity's foreign zone wherethe said network has been declared by the mobile entity as its foreignnetwork, e.g., an IP subnetwork in a foreign zone of a mobile entity.

Care-of Network Address: the address of the network point of attachmentin a foreign network of a mobile entity, e.g., IP address (RAS transportaddress) in a foreign IP subnetwork. If the transport address containsthe network address in addition to the TSAP, the care-of transportaddress will also contain the care-of network address.

Visiting GK: a foreign GK that the mobile entity is presently visiting,i.e., the mobile entity is currently residing within a foreign zone thatis managed by a foreign GK.

Visited GK: the foreign GK that had been visited by the mobile entitypreviously.

Target GK: the foreign GK that the mobile entity intends to visit.

Target Network: the target network that the mobile entity intends tovisit.

Mobile GK: either a home GK or a foreign GK.

Home Zone: a zone that is managed by a home GK of a mobile entity.

Foreign Zone: a zone managed by a foreign GK.

Visiting Zone: a zone other than a mobile entity's home zone in whichthe mobile entity is currently residing, i.e., a foreign zone in whichthe mobile entity is presently visiting.

Visited Zone: a zone other than a mobile entity's home zone that themobile entity has visited previously, i.e., the foreign zone which hadbeen visited by the mobile entity previously.

Target Zone: a zone other than a mobile entity's home zone that themobile entity intends to visit.

Visiting Entity: a mobile entity that is residing in a visiting zonemanaged by a visiting GK.

Visiting Terminal: a mobile H.323 terminal that is residing in avisiting zone managed by a visiting GK.

Visiting User: a mobile H.323 terminal that is residing in a visitingzone managed by a visiting GK.

Visitor List: the list of mobile entities currently visiting a foreignzone.

GK Advertisement for Mobility Services: foreign gatekeepers advertisetheir presence by using a special message to provide services for mobileentities.

Care-of Address: the terminal address of the point of attachment, e.g.,care-of network address of mobile entity or care-of address of a foreignGK where a mobile entity is residing.

There are two different types of care-of address: a foreign GK care-ofaddress with which a mobile entity is Databased; a care-of networkaddress which the mobile entity has associated with one of its ownnetwork interfaces, e.g., a temporary IP address of the visitor may beacquired dynamically using the Dynamic Host Configuration Protocol(DHCP).

Location Area: a location area may constitute a cell or a certain groupof cells in a given geographical area that resides within a zone.

Administrative Domain: An administrative domain is a collection of H.323entities administered by one administrative entity and may contain oneor more gatekeepers (that is, one or more zones). It may also containone or more border elements for communications between the domains. Likezone, an administrative domain can also be termed as home or foreign(visited, visiting, or target) domain.

Mobile H.323 (Mobile H.323 Protocol): the extended and existing H.323/H.225.0/H.245 messages that are used to support mobility in H.323 aretermed as mobile H.323 protocol or simply as mobile H.323.

Clearly, H.323 mobility provides two kinds of changes in point ofattachment: changing Network Point of Attachment in H.323 to H.323 calls(it can also be termed as a part of change in H.323 point ofattachment), and changing H.323 Point of Attachment (e.g., change inzone or domain). Broadly speaking, both kinds of change in attachmentcan be termed as change in H.323 point of attachment. The change ofattachment can also occur during calls, i.e., handover, and betweencalls, e.g., roaming. A change in point of attachment, e.g., a change inIP address or a change in zone/domain boundary, may result in handoverduring the call.

FIG. 1 illustrates an embodiment of the Inter-Domain Mobility Managementsystem of this invention which illustrates communications between twoadministrative domains. Administrative domain 10 has a GK/BE_(1b) 12, aGK_(1a) 14 and a GK_(1c) 16. Administrative domain 20 has a GK/BE_(2b)22, a GK_(2a) 24 and a GK_(2c) 26. A mobile H.323 entity 28 contacts theGK_(2c b) 26 after moving from administrative domain 10 toadministrative domain 20. Basically, the mobile entity 28 will discoverthe gatekeeper (GK) and then communicate with the gatekeeper (GK) forregistration using the procedures as described in ITU-T RecommendationH.323, such as, GK_(2c) 26 of the administrative domain 20 of a givenadministrative domain. The Gate-keeper (GK) 26, will find from theregistration request message that the mobile user has moved from anotheradministrative domain and needs to communicate with the otheradministrative domain. As result, GK_(2c) 26 of the administrativedomain 20 will then communicate with a border element (BE) 22 of thatadministrative domain 20 as appropriate depending on the needs dictatedby the optimal routing so that minimal resources are used. The borderelement (BE) 22 will then communicate with another border element (BE)12 of administrative domain 10 for resolving the information (e.g.,address, registration, verification, authentication, etc.).

Gatekeeper discovery is the process an endpoint uses to determine whichGatekeeper to register with. This may be done manually or automatically.Manual discovery relies on methods outside the scope of thisrecommendation to determine which Gatekeeper an endpoint is associatedwith. The endpoint may multicast (or use other methods as described inAppendix IV/H.225.0) a Gatekeeper Request (GRQ) message, asking “Who ismy Gatekeeper?”. This is sent to the Gatekeeper's well-known DiscoveryMulticast Address. One or more Gatekeepers may respond with theGatekeeper Confirmation (GCF) message indicating “I can be yourGatekeeper.”, and return the Transport Address of the Gatekeeper's RASChannel. If a Gatekeeper does not want the endpoint to register to it,it shall return Gatekeeper Reject (GRJ).

It should be appreciated that FIG. 1 shows the logical communicationsmodel between the two administrative domains where no backend services(BES) are considered. BES provide additional value-added services, suchas, for example, permanent and/or temporary addressresolution/allocation services, authentication, and others using thedatabase/server not defined in H.323 and also not shown in FIG. 1.

FIG. 2 illustrates another embodiment of the Inter-Domain MobilityManagement system of this invention which basically describes thecommunications flow when the backend services (BES) (e.g., home locationfunctions (HLFs)) are considered. Like FIG. 1, it is assumed that mobileentity 28 has moved from administrative domain 30 to administrativedomain 40 and performs the GK discovery and registers with the GK_(2c)26 using H.323 procedures as described earlier. The relationships forcommunications between border elements (BEs) and backend services (BES)(e.g., home location function (HLFs)) and gate keepers (GKs) needs to bedone in accordance with H.323 standards. The backend services (BES) of agiven administrative domain can equally be accessed by both thegatekeeper (GK) and the border element (BE). However, a user can sendthe request for any services via the gatekeeper (GK). Upon receipt of arequest for backend services the GK will examine the request and willdetermine that the user has moved from another administrative domain andthat the related service information needs to be known from the earlierBES that is not located in this domain 40. Then the gatekeeper (GK)decides how the backend services (BES) can be accessed to anotheradministrative domain using the Border elements (BEs). Depending on theconfiguration between the administrative domains optimal routing will beprovided to optimize the resource utilization. Normally the Borderelement (BE) is accessed if the services information needs to beresolved from another administrative domain. In this context FIG. 2shows that the backend services (BES) are being accessed from anotheradministrative domain via the border elements (BEs). As describedearlier, a user or mobile H.323 entity 28 needs to send the servicerequest to the GK where the user or H.323 mobile entity has registered.As a result, when the user 28 enters administrative domain 40, thecommunication is sent to a gatekeeper 26, which routes it to the borderelement 22. The communication is then sent to border element 12 inadministrative domain 30 and then routed to backend services 32. Therequest that is sent from the mobile user or H.323 mobile entity 28located in administrative domain 40 to the BES_(1b) 32 via GK 26, BE 22,and BE 12, is resolved in BES 32 of administrative domain 30 and, areply is sent back by the BES 32 to the mobile entity 28 via BE 12, BE22, and GK 26. Administrative domain 30 will have a plurality ofgatekeepers 14, 16 and backend services 34 (BES1 _(a)), 36 (BES_(1c)).Similarly, the Administrative domain 40 will have a plurality ofgatekeepers 24, 26 and backend services 42 (BES_(2b)), 44 (BES_(2a)),46(BES_(2c)). In the same token, there can be a plurality of borderelements (BEs) in each administrative domain and has not been shown forsimplicity. However, FIG. 2 also shows that the backend services (BES)(e.g., home location functions (HLFs)) information resolution isprovided from another administrative domain for an H.323 mobile entityif the information is not available in a given administrative domain.

FIG. 3 illustrates yet another embodiment of the Inter-Domain MobilityManagement system of this invention where the backend services (BES)(e.g., home location function (HLFs)) overlap or are common to both theadministrative domains, and where requests are resolved by the backendserver shared among multiple administrative domains. FIG. 3 shows aconfiguration 50 where a given back end services (BES) server 55 isbeing shared or is common between the two administrative domains,namely, administrative domain 30 and administrative domain 40. It shouldalso be noted that there may be other back end services (BES) servers inthose domains whose services are not being shared. As a result, theservices from the non-sharing back end services (BES) server has to beaccessed using the normal procedure of the H.323 protocol viagatekeepers (GKs) and/or border elements (BEs). Also shown is a mobileH.323 entity 38.in the administrative domain that would also be sharingthe back end services (BES) server 55, and getting similar informationwhether it is within the home domain or in a foreign domain.

FIG. 4 illustrates still another embodiment of the Inter-Domain MobilityManagement system of this invention showing the accessing of anon-sharing back end services (BES) server in two overlappingadministrative domains. The non-shared backend services (BES) server(e.g., BES_(1a) 34) needs to be accessed although a given back endservices (BES) server (or servers) may be shared because of theoverlapping administrative domains, and where requests are resolved bythe backend server not shared among multiple administrative domains.FIG. 4 also illustrates how the inter-domain communication needs to bedone in the context of H.323 communications protocol. The H.323signaling messages for inter-domain communications flows from the borderelement (BEs) 22, to the border element 12 between the administrativedomains 40, 30, as discussed earlier. However, the backend services(BES) from a back end services (BES) server that reside behind a gatekeeper (GK) and/or a border element (BE) may be accessed via the gatekeeper (GK) and/or border element (BE) as appropriate. The non-sharedbackend services (BES) server BES_(1a) 34 is then accessed although thegatekeeper 14. However, it should be understood that a given back endservices (BES) server (or servers) may be shared because of theoverlapping administrative domains, and where requests are resolved bythe backend server and are not shared among multiple administrativedomains. The services from a back end server (BES) 34 can only berequested by an H.323 endpoint 28, 38 via a gate keeper (GK) 14 (becausea border element (BE) is not directly accessible by an H.323 endpoint(e.g., terminal, GW (gateway)). Furthermore, the mobile entity 28, 38moves from one place to another and may not be aware whether it isattached to its home network address, home zone, and/or home domain. Itis expected that the MGA (mobile gatekeeper advertisement) message thathelps to discover the gatekeeper (GK) for the mobile entity to receiveservices for receiving or sending calls will provide this information orsome other mechanisms will help the mobile H.323 entity to discover thatit is in a new administrative domain. When the mobile entity is in aforeign (visiting) administrative domain, it may so happen that there isa need to verify mobile entity's profile for proper identification,authorization, and other purposes from its home domain. If a mobileentity does not need to verify its profile from its home domain, thereis almost no need for any new standard work in H.323 for mobilitybecause re-registration mechanisms that exits in H.323 may be sufficientfor this purpose.

Inter-zone communications and the inter-domain communications will alsoneed the following: (a) Gate-keeper (GK) discovery and identificationwhether it is in its home domain or in foreign domain, (b) Registrationwith the gate keeper (GK), (c) Location updates, (d) Smooth locationupdates, (e) Call establishment.

Communications between the administrative domains are done via borderelements (BEs) and gate-keepers (GKs) when there are back end services(BES) servers as discussed earlier. The back end services (BES) serverresides behind the gate-keepers (GKs) and border elements (BEs). Thehome location function (HLF) and visitor location function (VLF) arealso considered as back end services (BES) servers that are used forstorage of information related to mobility. The relationship between theborder elements (BEs), home location function (HLFs), visitor locationfunction (VLFs), and gate keepers (GKs) for H.323 communicationsprotocol is the same as described in the context of Back end services(BES) servers.

FIG. 5 illustrates yet another embodiment of the Inter-Domain MobilityManagement system of this invention using a centralized home locationfunction (HLF) server/database. FIG. 5 also shows the communicationsflows when a mobile entity moves from one administrative domain toanother where each domain has only one home location function (HLF)configured in a centralized architecture. In this embodiment the mobileentity discovers the gatekeeper (GK_(2c)) and finds that its is in aforeign (visiting) domain. Then the mobile entity proceeds withregistration with the gatekeeper (GK) (GK2c). The gatekeeper (GK2c)finds that mobile H.323 entity 28 is a visitor and keeps the informationin the visitor location function (VLF) (not shown in FIG. 5 forsimplicity). There can be some communications between the visitorlocation function (VLF), GK2c, and HLF2b to find out if mobile H.323entity 28 is a visitor from another domain (similar one described in R.R. Roy, AT&T, “H.323 Inter-Zone Mobility Management,” MD018, Ad HocMobility Conference Call, February-May 2000, the disclosure of which isentirely incorporated herein by reference, in the context of inter-zonemobility management), and the communication flow between gatekeeper andgatekeeper from or within one s domain has not been shown in FIG. 5 forsimplicity. Then, GK2c 26 contacts the border element (GK/BE2b) 22 tocontact the administrative domain 75 for verifying the visitor'sprofile. The border element (GK/BE2b) 22 of the foreign domain 75 beingunable to provide the information related to the mobile H.323 entity 28then contacts the border element (GK/BE1b) 12 of mobile entity's homedomain 70. There is only one home location function (HLF) 72 in the homeadministrative domain 70 because of the centralized configuration, andGK/BE1b 12 communicates with HLF1b 72 directly to verify the profile ofthe mobile entity 28 that is currently residing in administrative domain75. The information is then sent back from the home domain 70 to theforeign (visiting) administrative domain 75 after verifying the profileof the mobile entity 28. (These information flows are not shown in FIG.5 for simplicity.) Administrative domain 75 may have additional homelocation functions HLF2b (78) that may be available for additionalinformation.

FIG. 6 illustrates still another embodiment of the Inter-Domain MobilityManagement system of this invention showing the inter-domaincommunication flow using distributed home location function (HLF)servers/databases. FIG. 6 also shows a configuration for communicationsbetween the two administrative domains where the home location function(HLF) function is distributed in a domain. The communications scenariosare almost similar as shown in FIG. 5, but with the difference that agate-keeper (GK) has the intelligence to decide which home locationfunction (HLF) is needed to be accessed for resolving the information.However, how the decision is made by the gate-keeper (GK) for contactinga particular gate keeper (GK) and/or home location function (HLF) is notthe subject of standardization. For example, when the border element(GK/BE2b) 22 of the foreign (visiting) domain 75 communicates withborder element (GK/BE1b) 12 of the home administrative domain 70,GK/BE1b 12 decides that this particular mobile entity 28 is managed byGK1a 14 and contacts GK1a 14. The gatekeeper (GK1a) 14 will thencommunicate with HLF1a 84 to verify the profile of the mobile entity 28that is currently residing in a foreign domain 90. The informationrelating to the mobile entity 28 that is obtained is then routed backfrom the home administrative domain 80 to the foreign administrativedomain 90. This information relating to the mobile entity 28 may betemporarily or permanently stored in HLF2b 92 in the foreignadministrative domain 90. Both administrative domains 80 and 90 may haveadditional home location functions HLF1c (86), HLF2a (94), HLF2b (92),HLF2c (96) that may be available for additional information.

It may be noted that the communications between the visitor locationfunction (VLF) and home location function (HLF) after registration ofthe mobile entity in a visiting (foreign) domain in view of thedistributed Home location function (HLF) will be almost similar to thatdescribed in AT&T's contribution for inter-zone mobility management,namely, R. R. Roy, AT&T, “H.323 Inter-Zone Mobility Management,” MD018,Ad Hoc Mobility Conference Call, February-May 2000, the disclosure ofwhich is entirely incorporated herein by reference.

In R. R. Roy, AT&T, AH.323 “Mobile Communications Environments andIntra-Zone Mobility Management,” MD017, Ad Hoc Mobility Conference Call,February-May 2000, and R. R. Roy, AT&T, “Needs for Creation of NewMobility Binding Messages Exclusively for H.323 Mobility Management”,APC-1769, SG16, Q.13/16, WP2, Osaka, Japan, May 15-19, 2000, thedisclosures of which are entirely incorporated herein by reference, ithas been explained why there is a need for creation of separatesignaling messages for mobility binding and updating in addition toextensions of existing messages to support mobility. The characteristicsof the mobility binding and updating messages are such that the existingH.323 signaling messages do not have the properties to satisfy thoserequirements. The new mobility binding and updating messages proposed incontribution, such as, R. R. Roy, AT&T, “H.323 Mobility Architecture andProtocol for Terminal, User, and Service Mobility,” D-354, ITU-T SG 16Q.13/16, WP2, Geneva, Switzerland, Feb. 7-18, 2000, the disclosure ofwhich is entirely incorporated herein by reference, can also be used forinter-domain communications.

However, the existing accessRequest and other messages of H.225.0 AnnexG, for inter-administrative domain communications also need to beextended to support mobility. It may be noted that we still need tocreate new messages for mobility binding and updating as suggested in R.R. Roy, AT&T, “H.323 Mobility Architecture and Protocol for Terminal,User, and Service Mobility,” D-354, ITU-T SG 16 Q.13/16, WP2, Geneva,Switzerland, Feb. 7-18, 2000, the disclosure of which is entirelyincorporated herein by reference.

The new messages that support mobility binding and updating has beenproposed in R. R. Roy, AT&T, “H.323 Mobility Architecture and Protocolfor Terminal, User, and Service Mobility,” D-354, ITU-T SG 16 Q.13/16,WP2, Geneva, Switzerland, Feb. 7-18, 2000, the disclosure of which isentirely incorporated herein by reference. The same messages can be usedfor both intra-domain and inter-domain communications. For inter-domaincommunications additional message headers like hopcount and others needto be added.

Like LRQ (Location Request), we also need to extend the accessRequestand few other messages to indicate where the RAS (Registration,Admission, and Status) and call signaling addresses need to be sent forthe mobile entity while the mobile entity will move from one place toanother. Moreover, a mechanism that allows whether the mobile entitywill let others know its actual location other than its original homenetwork address for a single, multiple or all media (may be basedsubscription policy like security or otherwise) while it is in a foreigndomain is also need to be kept as an option.

It has clearly been articulated how the inter-domain communications needto be made to manage mobile entity users that conforms the existingH.323 standard. In particular, it has been shown that the relationshipand communications flows among the border elements (BEs), gate keepers(GKs), home location function (HLFs), and visitor location function(VLFs) considering the following:

(a) Border elements (BEs) can be configured as centralized,distributive, and/or hybrid architecture.

(b) Gatekeepers (GKs) can have any architectural relationships:centralized, distributive, and/or hybrid architecture.

(c) Home location function (HLFs) that are considered as the backendservers behind the Border elements (BEs) and Gate keepers (GKs) can alsobe arranged in any architectural relationship with respect to the Borderelements (BEs) and Gate keepers (GKs): centralized, distributive, and/orhybrid architecture.

(d) The administrative domains can also be arranged logically amongthemselves in any form: centralized, distributive, and/or hybridarchitecture.

(e) The overlapping administrative domains that can have the sharedbackend services (e.g., Home location function (HLF)).

The inter-domain communications protocol for mobility management needsto be robust enough to satisfy all probable configurations of allfunctional entities (e.g., border elements (BEs), gate keepers (GKs),home location function (HLFs), visitor location function (VLFs), zones,domains) whether each architectural element is configured ascentralized, distributed, and/or hybrid manner. However, the back endservices (BES) server (e.g., home location function (HLF)) to back endservices (BES) (e.g., home location function (HLF)) servercommunications protocol is not the scope of H.323.

The invention provides a framework for how the inter-domaincommunications need to be done in H.323 for mobility management. It hasbeen shown the communication flows for mobility management consideringthe border elements (BEs), gate keepers (GKs), home location function(HLFs), and domains where each entity can be arranged in any logicalarchitectural relationship: centralized, distributed, and/or hybridarchitecture.

In addition, the messages like accessRequest and other are also need tobe extended to let others know the RAS and the call signaling addressesof the mobile entity while it is visiting a foreign domain. Furthermore,it is the critical need for a mobile entity to have an option whether itwill let others to know its present location in a foreign domain whileit is away from its home domain because the communications can also bedone via its home network address that it may want make to public.

This invention also shows various relationships for communicationsbetween border elements (BEs), home location function (HLFs), visitorlocation function (VLFs), and gate keepers (GKs).

H.225.0 Annex G provides the communications between the administrativedomains via the border elements (BEs). A domain may have one or moreborder elements (BEs) while these border elements (BEs) may have thelogical relationship, such as, (a) centralized, (b) distributed, or (c)hybrid architecture.

A Border element (BE) is usually co-located with a gatekeeper (GK). Ifthey are not co-located, the communications between the border element(BE) and the gatekeeper (GK) will be done using the H.225.0 RASsignaling messages (e.g., LRQ/LCF/LRJ) for the address resolution andlocation update.

However, it is felt that it would be more efficient to use the H.225.0Annex G messages between the gatekeepers (GKs) as well as between thegatekeeper (GK) and the border element (BE).

Furthermore, the administrative domains can also be arranged amongthemselves, such as (a) centralized, (b) distributed, or (c)hybrid.architectural relationship from logical communications point ofview.

There may also be overlapping administrative domains and more than oneadministrative domain that may be able to resolve a given address.

A border element (BE) element configures itself with all addressinformation obtaining the address templates in the following ways (a)static configuration with explicit provisioning with address templatesfor all zones for which it is responsible, (b) receiving descriptorscontaining the address information from other border elements (BEs) inresponse to general requests, and (c) receiving responses to specificqueries.

It is important to understand that home location function (HLFs)/visitorlocation function (visitor location function (VLFs)) can be accessedequally by border elements (BEs) and gatekeepers (GKs). However, amobile entity can only communicate with the gatekeeper (GK) directly(not the border element (BE)).

The H.323-based mobility Mobile Terminal/Node/Entity registers with theH.323 Visiting/Foreign Gatekeeper including sending registrationinformation for the Mobile Terminal/Node/Entity using a Base Station toBase Station Controller to Mobile Switching Center to H.323Visiting/Foreign Gatekeeper system. Wherein registering with the atleast one H.323 Visiting/Foreign Gatekeeper includes sendingregistration information for the Mobile Terminal/Node/Entity using awireless/wire-line Local Area Network to Router/Switch to H.323Visiting/Foreign Gatekeeper system. Furthermore, the registeringincludes the steps of: broadcasting/multicasting/unicasting /sending, bythe Home Gatekeeper, a Mobility Gatekeeper Advertisement (MGA) messageperiodically; broadcasting/multicasting/unicasting/sending aregistration request message (RRQ) to the Home Gatekeeper by the MobileTerminal/Node/Entity; and sending, by the Home Gatekeeper, aregistration confirmation/registration rejection (RCF/RRJ) to the MobileTerminal/Node/Entity. The registering steps can also include the stepsof: upon determining, by the Mobile Terminal/Node/Entity, that a networkpoint of attachment has changed/a foreign zone has been entered,broadcasting/multicasting/unicasting /sending, by the MobileTerminal/Node/Entity, a registration request message (RRQ) to aForeign/Visiting Gatekeeper; broadcasting/multicasting/unicasting/sending, by the Foreign/Visiting Gatekeeper, a binding update message(BURQ) to the Home Gatekeeper;broadcasting/multicasting/unicasting/sending, by the Home Gatekeeper, abinding update confirmation/rejection (BuCF/BuRJ) to theForeign/Visiting Gatekeeper;broadcasting/multicasting/unicasting/sending, by the Foreign/VisitingGatekeeper, the binding update confirmation/rejection to the MobileTerminal/Node/Entity.

The H.323-based mobility Mobile Terminal/Node/Entity would also includea situation wherein, where the Mobile Terminal/Node/Entity has alreadyvisited another zone regulated by a Visited Gatekeeper within the firstadministrative domain, registering includes:broadcasting/multicasting/unicasting/sending, by the Home Gatekeeper, amobility unbinding message (UbRQ) to the Visited Gatekeeper; andbroadcasting/multicasting/unicasting/sending, by the Visited Gatekeeper,a mobility unbinding confirmation/rejection (UbCF/UbRJ) to the HomeGatekeeper. Or, where the H.323-based Mobile Terminal/Node/Entity hasalready visited another zone regulated by a Visited Gatekeeper withinthe first administrative domain, registering would include:

-   broadcasting/multicasting/unicasting/sending, by the Mobile    Terminal/Node/Entity, a registration request message (RRQ) to a    Foreign/Visiting Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the    Foreign/Visiting Gatekeeper, a mobility unbinding update message    (UbRQ) to the Visited Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the Visited    Gatekeeper, a mobility unbinding confirmation/rejection (UbCF/UbRJ)    to the Foreign/Visiting Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the    Foreign/Visiting Gatekeeper, a provisional registration confirmation    to the Mobile Terminal/Node/TerminalEntity and-   broadcasting/multicasting/unicasting/sending, by the    Foreign/Visiting Gatekeeper, a binding update message (BuRQ) to the    Home Gatekeeper; and broadcasting/multicasting/unicasting/sending,    by the Home Gatekeeper, a binding update confirmation/rejection    (BuCF/BuRJ) to the Foreign/Visiting Gatekeeper.

The H.323-based Mobile Terminal/Node/Entity having already visitedanother zone regulated by a Visited Gatekeeper within the firstadministrative domain, and wherein registration could include:

-   broadcasting/multicasting/unicasting/sending, by the Mobile    Terminal/Node/Entity, a registration request message (RRQ) to a    Foreign/Visiting Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the Visited    Gatekeeper, a mobility unbinding confirmation/rejection (UbCF/UbRJ)    to the Foreign/Visiting Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the    Foreign/Visiting Gatekeeper, a provisional registration confirmation    to the Mobile Terminal/Node/Terminal and    broadcasting/multicasting/unicasting/sending, by the    Foreign/Visiting Gatekeeper, a binding update message (BuRQ) to the    Home Gatekeeper; broadcasting/multicasting/unicasting/sending, by    the Home Gatekeeper, a binding update confirmation/rejection    (BuCF/BuRJ) to the Foreign/Visiting Gatekeeper;    broadcasting/multicasting/unicasting/sending, by the Home    Gatekeeper, a mobility unbinding update message (UbRQ) to the    Visited Gatekeeper; and    broadcasting/multicasting/unicasting/sending, by the Visited    Gatekeeper, a mobility unbinding confirmation/rejection (UbCF/UbRJ)    to the Home Gatekeeper.

The H.323-based mobility Mobile Terminal/Node/Entity wherein at leastone Visiting/Foreign Gatekeeper utilizes a combined HomeVisitor LocationDatabase. The H.323-based mobility Mobile Terminal/Node/Entity wherein aplurality of Visiting/Foreign Gatekeepers each utilize an individualVisitor Location Database and share a Home Location Database. TheH.323-based mobility Mobile Terminal/Node/Entity wherein thecommunication utilizes an Internet Protocol.

This invention provides a communication link between a telephone deviceand/or another telephone device(s) and/or server(s). It also allows forprogramming a telephone device to accept or reject communicationsbetween administrative domains. This invention also allows a mobileentity unit to be in communication with a telephone network, especiallywhen a user moves between different administrative domains.

While the present invention has been particularly described, inconjunction with a specific preferred embodiment, it is evident thatmany alternatives, modifications and variations will be apparent tothose skilled in the art in light of the foregoing description. It istherefore contemplated that the appended claims will embrace any suchalternatives, modifications and variations as falling within the truescope and spirit of the present invention.

1. An inter-domain mobility management method, comprising: (a) a mobileH.323. entity communicating sending information related to the mobileentity with to a first gatekeeper in a first administrationadministrative domain; (b) said first gatekeeper being unable to verifysaid information on related to said mobile H.323 entity and sendinginformation to accessing a first border element within said firstadministration administrative domain to resolve said information relatedto the mobile entity; (c) said first border element communicatinginformation with accessing a second border element in a secondadministrative domain to resolve said information related to the mobileentity; (d) said second border element communicates sending back with tosaid first border element with information to resolve information thatresolves said information related to the mobile entity; and (e) saidsecond first border element accepting said resolved information relatedto the mobile entity and communicates said information with sending tosaid mobile H.323 entity via said first gatekeeper a reply to theinformation related to the mobile entity sent by said mobile H.323entity.
 2. The method of claim 1 wherein said information received byrelated to the mobile entity sent to said first gatekeeper istransferred via said second border element to a second gatekeeper withinsaid first second administrative domain.
 3. The method of claim 1wherein said second administrative domain is the a home administrativedomain for said mobile H.323 entity.
 4. The method of claim 1 whereinsaid first administrative domain is a serving, visiting, visited orforeign administrative domain for said mobile H.323 entity.
 5. Themethod of claim 1 wherein said first gatekeeper requests receives saidinformation related to the mobile entity to register, authenticate,verify, resolve, or allocate resources to said mobile H.323 entity. 6.An inter-domain mobility management method, comprising: (a) a mobileH.323 entity communicating sending information related to the mobileentity with to a first gatekeeper in a first administrative domainhaving a first backend services; (b) said first gatekeeper being unableto verify said information on related to said mobile H.323 entity andsending information to accessing a first border element within saidfirst administrative domain to resolve said information related to themobile entity; (c) said first border element communicating informationwith accessing a second border element in a second administrative domainto resolve said information related to the mobile entity; (d) saidsecond border element obtains information obtaining from a secondbackend services in said second administrative domain information thatresolves said information related to the mobile entity and communicatessending back with to said first border element with information toresolve said information related to the mobile entity the informationobtained from said second border element; and (e) said second firstborder element accepting said resolved information related to the mobileentity and communicates said information with sending to said mobileH.323 entity via said first gatekeeper a reply to the informationrelated to the mobile entity sent by said mobile H.323 entity.
 7. Themethod of claim 6 wherein said information received by related to themobile entity sent to said first gatekeeper is transferred via saidsecond border element to a second gatekeeper within said first secondadministrative domain.
 8. The method of claim 6 wherein said secondadministrative domain is the a home administrative domain for saidmobile H.323 entity.
 9. The method of claim 6 wherein said firstadministrative domain is a serving, visiting, visited or foreignadministrative domain for said mobile H.323 entity.
 10. The method ofclaim 6 wherein said first gatekeeper requests receives said informationrelated to the mobile entity to register, authenticate, verify, resolve,or allocate resources to said mobile H.323 entity.
 11. The method ofclaim 6, wherein the information obtained by said second border elementfrom said second backend services is stored within said first backendservices.
 12. The method of claim 6 wherein the information obtained bysaid second border element from said second backend services is storedwithin said first backend services and wherein subsequently said firstbackend services provides home location functions.
 13. The method ofclaim 6 wherein the information obtained by said second border elementfrom said second backend services is stored within said first backendservices and wherein subsequently said first backend services provideshome location functions, and wherein said home location functionsprovides at least one services selected from a group consisting ofaddress, registration, verification, resolution, allocation andauthentication.
 14. An inter-domain mobility management method,comprising: (a) a mobile H.323. entity communicating sending informationrelated to the mobile entity with to a first gatekeeper in a firstadministration administrative domain having a first backend services;(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administration administrativedomain to resolve said information related to the mobile entity; (c)said first border element communicating information with accessing afirst backend services to resolve said information related to the mobileentity, wherein said first backend services is shared with both by saidfirst administrative domain and a second administrative domain; (d) saidsecond first border element obtains information obtaining from saidfirst backend services in said first and said second administrativedomain information that resolves said information related to the mobileentity, and communicates sending it back to said first border elementwith information to resolve said information related to the mobileentity; and (e) said second first border element accepting said resolvedinformation related to the mobile entity and communicates saidinformation with sending to said mobile H.323 entity via said firstgatekeeper a reply to the information related to the mobile entity sentby said mobile H.323 entity.
 15. The method of claim 14 wherein saidinformation received by related to the mobile entity sent to said firstgatekeeper is transferred via said second border element to a secondgatekeeper within said first second administrative domain.
 16. Themethod of claim 14 wherein said second administrative domain is the ahome administrative domain for said mobile H.323 entity.
 17. The methodof claim 14 wherein said first administrative domain is a serving,visiting, visited or foreign administrative domain for said mobile H.323entity.
 18. The method of claim 14 wherein said first gatekeeperrequests receives said information related to the mobile entity toregister, authenticate, verify, resolve, or allocate resources to saidmobile H.323 entity.
 19. The method of claim 14 wherein a the mobileH.323 entity in said first administrative domain communicates with saidfirst backend services.
 20. An inter-domain mobility management method,comprising: (a) a mobile H.323. entity communicating sending informationrelated to the mobile entity with to a first gatekeeper in a firstadministration administrative domain having a first backend services;(b) said first gatekeeper being unable to verify said information onrelated to said mobile H.323 entity and sending information to accessinga first border element within said first administration administrativedomain to resolve said information related to the mobile entity; (c)said first border element communicating information with accessing asecond border element in a second administrative domain to resolve saidinformation related to the mobile entity; (d) said second border elementobtains obtaining information from a second backend services in saidsecond administrative domain via at least one a second gatekeeper insaid second administrative domain and communicates back with sendingback to said first border element with information to resolve saidinformation related to the mobile entity the information obtained fromthe second backend service; and (e) said second first border elementaccepting said resolved information related to the mobile entity andcommunicates said information with sending to said mobile H.323 entityvia said first gatekeeper a reply to the information related to themobile entity sent by said mobile H.323 entity.
 21. The method of claim20 wherein said information received by related to the mobile entitysent to said first gatekeeper is transferred via said second borderelement to a second gatekeeper within said first second administrativedomain.
 22. The method of claim 20 wherein said second administrativedomain is the a home administrative domain for said mobile H.323 entity.23. The method of claim 20 wherein said first administrative domain is aserving, visiting, visited or foreign administrative domain for saidmobile H.323 entity.
 24. The method of claim 20 wherein said firstgatekeeper requests receives said information related to the mobileentity to register, authenticate, verify, resolve, or allocate resourcesto said mobile H.323 entity.
 25. An inter-domain mobility managementmethod, comprising: (a) a mobile H.323. entity communicating sendinginformation related to the mobile entity with to a first gatekeeper in afirst administration administrative domain having a first locationfunction; (b) said first gatekeeper being unable to verify saidinformation on related to said mobile H.323 entity and sendinginformation to accessing a first border element within said firstadministration administrative domain to resolve said information relatedto the mobile entity; (c) said first border element communicatinginformation with accessing a second border element in a secondadministrative domain to resolve said information related to the mobileentity; (d) said second border element obtains obtaining informationfrom a second home location function in said second administrativedomain and communicates sending back with to said first border elementwith information to resolve said information related to the mobileentity the information obtained from said second location function; and(e) said second first border element accepting said resolved informationrelated to the mobile entity and communicates said information withsending to said mobile H.323 entity via said first gatekeeper a reply tothe information related to the mobile entity sent by said mobile H.323entity.
 26. The method of claim 25 wherein said information received byrelated to the mobile entity sent to said first gatekeeper istransferred via said second border element to a second gatekeeper withinsaid first second administrative domain.
 27. The method of claim 25wherein said second administrative domain is the a home administrativedomain for said mobile H.323 entity.
 28. The method of claim 25 whereinsaid first administrative domain is a serving, visiting, visited orforeign administrative domain for said mobile H.323 entity.
 29. Themethod of claim 25 wherein said first gatekeeper requests receives saidinformation related to the mobile entity to register, authenticate,verify, resolve, or allocate resources to said mobile H.323 entity. 30.The method of claim 25 wherein the information obtained by said secondborder element from said second home location function is stored withinsaid first home location function.
 31. The method of claim 25 whereinthe information obtained by said second border element from said secondhome location function is stored within said first home locationfunction and wherein subsequently said first home location functionprovides home location functions.
 32. The method of claim 25 wherein theinformation obtained by said second border element from said second homelocation function is stored within said first home location function andwherein subsequently said first home location function provides homelocation functions, and wherein said home location functions provides atleast one services selected from a group consisting of address,registration, verification, resolution, allocation and authentication.33. An inter-domain mobility management method, comprising: (a) a mobileH.323. entity communicating sending information related to the mobileentity with to a first gatekeeper in a first administrationadministrative domain having a first location function; (b) said firstgatekeeper being unable to verify said information on related to saidmobile H.323 entity and sending information to accessing a first borderelement within said first administration administrative domain toresolve said information related to the mobile entity; (c) said firstborder element communicating information with accessing a second borderelement in a second administrative domain to resolve said informationrelated to the mobile entity; (d) said second border element obtainsobtaining information from a second home location function in saidsecond administrative domain via at least one a second gatekeeper insaid second administrative domain and communicates sending back with tosaid first border with information to resolve said information relatedto the mobile entity element the information obtained from said secondlocation function; and (e) said second first border element acceptingsaid resolved information related to the mobile entity and communicatessaid information with sending to said mobile H.323 entity via said firstgatekeeper a reply to the information related to the mobile entity sentby said mobile H.323 entity.
 34. The method of claim 33 wherein saidinformation received by related to the mobile entity sent to said firstgatekeeper is transferred via said second border element to a secondgatekeeper within said first second administrative domain.
 35. Themethod of claim 33 wherein said second administrative domain is the ahome administrative domain for said mobile H.323 entity.
 36. The methodof claim 33 wherein said first administrative domain is a serving,visiting, visited or foreign administrative domain for said mobile H.323entity.
 37. The method of claim 33 wherein said first gatekeeperrequests receives said information related to the mobile entity to oregister, authenticate, verify, resolve, or allocate resources to saidmobile H.323 entity.
 38. The method of claim 33 wherein the informationobtained by said second border element from said second home locationfunction is stored within said first home location function.
 39. Themethod of claim 33 wherein the information obtained by said secondborder element from said second home location function is stored withinsaid first home location function and wherein subsequently said firsthome location function provides home location functions.
 40. The methodof claim 33 wherein the information obtained by said second borderelement from said second home location function is stored within saidfirst home location function and wherein subsequently said first homelocation function provides home location functions, and wherein saidhome location functions provides at least one services selected from agroup consisting of address, registration, verification, resolution,allocation and authentication.